A prominent gay Liberal Democrat has defected to the Conservative party, launching a bitter attack on the leadership of Ming Campbell.

Richard Porter, a former London Borough of Southwark councillor, is reported to be one of two current LibDem prospective parliamentary candidates to have switched their allegiance to David Cameron’s party.

Mr Porter was contacted by PinkNews.co.uk and confirmed his defection. The Liberal Democrats press office declined to comment on reports of defections at this time.

Mr Porter had already been chosen by Lib Dem activists to contest the Camberwell Peckham constituency for the party at the next election.

In the same seat in 2005 he won 18% of the vote and was in second place to MP and minister Harriet Harman.

Mr Porter, who wrote the Lib Dem manifesto for the LGBT community at the 2005 election, told influential blog Iain Dale’s Diary, : “Ming Campbell is a ‘has-been’ and since he has been in control of the party, they have been stuck firmly in reverse gear.

“After the election, I took time out to reflect on my own personal beliefs and values. Previously I thought that these values were best represented by the Liberal Democrats but I now believe that the principles of freedom from state interference, personal freedom, the environment and civil liberties are all areas where the Conservative Party leads the way.”

Mr Dale, one of the pioneers of political blogging in the UK, claims that in the past year six current or former parliamentary prospective candidates for the Lib Dems have defected to the Conservative Party.

John Barstow, a shop steward for USDAW and Liberal Democrat PPC in Tonbridgeand Malling in 2005 and Dr Tariq Mahmood, who stood in Uxbridge as the Liberal Democrat in 2005, have defected along with Adrian Childs, former candidate for West Suffolk, Jeff Clarke, former candidate for West Wirral, and Rene Kinsett, former candidate for Swansea West.